Interlock threshold

ABSTRACT

A threshold assembly for a doorway formed of an extruded aluminum shape and a plastic shape, the two shapes being interlocked. The plastic shape defines that part of the threshold inwardly of the bottom of a door and primarily exposed to inside temperatures. The aluminum shape defines a door sill and that part of the threshold which extends outwardly from the door and which is primarily exposed to outside temperatures.

[ Nov. 27, 1973 INTERLOCK THRESHOLD Inventors: James T. Cribben; Joseph J. Miller,

both of Merchanicsburg, Pa.

[73] Assignee: Capitol Products Corporation,

I Mechanicsburg, Pa. [22] Filed: Dec. 9, 1971 21 Appl. No.: 206,304

[52] US. Cl. 49/467 [SI] Int. Cl E06b 1/70 [58] Field of Search 49/467, 468, 469, 49/470, 471

[56] References Cited UNITED STATES PATENTS 3,148,419 9/1964 Straus et al. 49/469 3,346,994 10/1967 Kesler 49/470 3,083,420 4/1963 Tinflow 49/469 3,382,617 5/1968 St. Aubin..... 49/468 3,667,164 6/1972 Coppins 49/469 FOREIGN PATENTS OR APPLICATIONS 97,885 5/1961 Netherlands 49/469 Primary Examiner-Mervin Stein Assistant ExaminerPhilip C. Kannan Att0rneyD0nald L. Johnson et al.

[5 7 ABSTRACT A threshold assembly for a doorway formed of an extruded aluminum shape and a plastic shape, the two shapes being interlocked. The plastic shape defines that part of the threshold inwardly of the bottom of a door and primarily exposed to inside temperatures. The aluminum shape defines a door sill and that part of the threshold which extends outwardly from the door and which is primarily exposed to outside temperatures.

9 Claims, 2 Drawing Figures 23 27 2o e r 11 .1 a 24 5L5 s INTERLOCK THRESHOLD BACKGROUND OF THE INVENTION A threshold assembly is normally associated with doors, especially exterior doors, to exclude drafts, dust, water and insects. One form of conventional threshold assembly includes an extruded threshold plate, usually of aluminum, which receives a hollow resilient member or bubble, usually of a vinyl material, which resiliently engages the bottom of the door when the threshold plate is mounted on the doorsill. With this type of construction, a large portion of the metal plate is exposed to inside temperatures and heat is readily conducted from the inside to the outside.

The present invention relates to an improved combination plastic and metal threshold construction or assembly which retards thermal conductivity of heat out of a home or building.

The instant invention particularly relates to thresholds for use in doorways having a door hinged therein.

Another type of prior art threshold structure is exemplified in U. S. Pat. No. 3,346,994. The threshold assembly is formed of three extruded aluminum shapes and a strip of insulating material, with two of the shapes being interlocked and defining that part of the threshold outwardly of the bottom of a door and which is exposed to outside temperatures. The third shape or base plate is mechanically interlocked with the insulating material which is in turn interlocked with the first two shapes, with the third shape extending inwardly from the door thermally insulated from the first two. A strip of resilient insulating material is also carried by the bottom edge of the door in position to sealingly engage the threshold. The present invention has a number of advantages over such prior art thresholds.

Another recent threshold assembly, application Ser. No. 193,390, filed Oct. 28, 1971 and having a common assignee provides additional improvements in the threshold art. The present invention provides an improvement of this threshold structure, wherein the portion of the threshold extending outwardly from the door and more exposed to wear and weather is made of metal or other suitable material. A particular advantage of the instant invention over said threshold assembly is that less materials are required thus efiecting a substantial savings in manufacturing costs.

The present invention not only provides an improved thermal barrier threshold but also one which can be produced more economically.

Other objects and advantages of this invention will be more readily apparent from the drawingsand description herein.

SUMMARY OF THE INVENTION The present invention comprises two basic parts, an extruded aluminum shape or sill and a continuous plastic threshold, preferably made from PVC or other suitable rigid and strong plastic, which two parts are interlockingly engaged. The metal part defining the sill also forms a part of the threshold and has means thereon which engage protruding members or legs extending from the plastic part defining the other part of the threshold. The members of one part are so constructed that they interlock with their respective members on the other part.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view representing a cross-section of the complete threshold assembly of the present invention in its installed position; and,

FIG. 2 is a perspective view of an end section of the plastic member and the metal sill of the threshold,

showing the two parts separately and illustrating how they are joined together.

DESCRIPTION OF THE PREFERRED EMBODIMENT as by means of screws 4. The outer edge or flange 5 of the base plate 2 has a plurality of openings 6 therein for receiving the screws 4. The openings 6 are spaced apart at suitable intervals longitudinally along the flange 5 of the sill 2. The base plate 2 includes a generally horizontal base plate portion 7 which lays on the upper surface of the header 8. The base plate portion 7 extends upwardly to define a threshold portion 9, and integral with the upper part thereof is longitudinal groove or channel 10. One side of the groove 10 extends downwardly or vertically to form a leg 11. The lower portion of the leg 11 extends to form a footing member 12 which is adapted to rest on the header or sub-floor 8. The leg 11 also has a projection member 13 integrally formed therewith and extending outwardly thereof.

The base plate portion 7 is illustrated as extending outwardly beyond the illustrated confines of the doorway and is configured to form an outer edge surface 14 in addition to defining the attached part or flange 5. The outer edge portion 14 is provided with an undercut groove 15 extending thereacross and in which a suitable resilient strip of vinyl, felt or other desired material may be positioned. The strip serves as a weather stripping for engagement with an auxiliary door such as a storm or screen door, not shown. The outer edge surface 14 may be smooth and the groove 15 eliminated, if desired.

It should be understood that the sill 2 is of an elongated shape and extends across the doorway from side to side thereof, as do all of the parts described herein.

The other component of the threshold structure A is a non-metallic threshold or partial threshold 20. The threshold member 3 is preferably made of plastic and a polyvinyl chloride (PVC) plastic is especially preferred. The member 20 is a one-piece longitudinal member which is adapted to interlockingly engage with the partial threshold and base plate 2. The partial threshold 20 is connected to the sub-floor 8 by any suitable means such as screws 21. Openings 22 are provided at suitable intervals longitudinally along the upper or fiat portion 23 of the member 20 upon which the lower edge of a door is adjacent thereto when the door is in a closed position. One leg 24 of the member 20 is curved outwardly and downwardly and forms a flange or extended leg which has an enlarged portion or base 25 at the end thereof which rests on the header or frame member 8. A second leg 26 of the threshold 20 extends outwardly away from the flat portion 23 and away from the leg 24 and has an enlarged projection or male member 27 at the end thereof which interlocks with the groove on the sill 2. Another member or leg 28 extends downwardly from the flat portion 23 also being integrally formed therewith and terminates ina hook 29. The hooked member 29 is adapted to interlock with the projection member 13 of the sill 2. The member 20 is thus snapped or locked into position on the sill 2 thereby forming the integral thermal barrier threshold A. Since the member 20 is non-metallic, a complete thermal barrier is obtained. Such construction also facilitates the repair or replacement of damaged thresholds.

It can readily be seen that screws or other suitable fasteners can be placed at a variety of locations as desired without departing from the scope of the present invention.

The base plate or sill 2 and the threshold 20 may be made to any predetermined length, width or depth desired to accommodate a particular doorway. Although various materials having necessary strength and rigidity may be used in constructing the novel threshold structure or assembly of this invention, in order to effect a good thermal barrier, the threshold 20 should preferably be of non-metallic material when the sill is metal.

Aluminum is defined herein as including aluminum and aluminum alloys having sufficient structural integrity to be employed in the manufacture of thresholds and those aluminum materials customarily employed in the threshold construction area.

Plastic is defined in the usual sense and includes those plastics having sufficient structural integrity to be employed in the manufacture of thresholds and those plastic materials customarily employed in the threshold construction area. In addition to PVC plastic, ABS, styrene, fiberglass, reinforced plastic and the like materials suitable for use in the instant invention are included in the term plastic.

The foregoing disclosure and description of the invention is merely illustrative and explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made within the scope of the appended claims without departing from the spirit of the invention.

What is claimed is:

1. A threshold structure for a doorway, comprising: a generally horizontal metal sill and partial threshold for extending across the bottom of the doorway; a generally horizontal plastic partial threshold for extending horizontally across the doorway and for being locked on said metal sill and partial threshold; a portion of said metal sill and partial-threshold extending upwardly and inwardly to form a partial threshold; a portion of said plastic partial threshold extending outwardly and downwardly away from said metal sill and partial threshold and free of contact therewith; locking means on said metal sill and partial threshold for interlockingly receiving locking means on said plastic partial threshold; and locking means on said plastic partial threshold for interlockingly receiving said locking means on said metal sill and partial threshold; said locking means on said metal sill and partial threshold comprising an upwardly facing groove and a down wardly extending leg having a projection outwardly thereon on said partial threshold, said groove and said leg being spaced apart and extending longitudinally and parallel to each other; and, said locking means on said plastic partial threshold comprising a downwardly extending leg having a projection thereon integrally formed therewith for being interlockingly received by said groove on said partial threshold on said metal sill and partial threshold and a downwardly and vertically extending leg having a hooked member thereon and integrally formed therewith for being interlockingly received by said outwardly extending projection on said downwardly extending leg on said metal sill and partial threshold; whereby when each of said locking means are engaged, said plastic partial threshold and said metal sill and partial threshold are locked together.

2. A threshold structure as defined in claim 1, wherein said metal sill and partial threshold extends outwardly of the doorway then downwardly to define an outwardly facing edge surface.

3. A threshold structure as defined in claim 2, wherein said outwardly facing edge surface has an undercut groove therein and extending longitudinally across the doorway said groove being adapted to receive a resilient strip of material for projecting from said edge surface for yieldable engagement with an auxiliary door.

4. The threshold structure of claim 1, wherein said metal sill and partial threshold is a single piece of aluminum and said plastic partial threshold is a single piece of plastic.

5. The threshold structure of claim 1, wherein said metal sill and partial threshold is an extruded aluminum shape and said plastic partial threshold is a PVC plastic shape.

6. The threshold structure of claim 1, wherein said downwardly and vertically extending leg on said plastic partial threshold terminates at said hooked member.

7. A threshold structure for a doorway consisting essentially of two one-piece components, a metal partial threshold and sill for extending horizontally across the bottom of the doorway and a plastic partial threshold for extending horizontally across the doorway on said metal sill, a portion of said metal sill extending up wardly and inwardly; leg means on said plastic partial threshold extending downwardly and outwardly away from said metal sill and free of contact therewith; and a pair of integrally formed means on each of said upwardly and inwardly extending portion of said metal sill and said plastic partial threshold which are slidably engageable with each other; said means for slidably engaging said metal sill with said plastic partial threshold comprising an upwardly facing groove means and vertically extending leg on said upwardly and inwardly extending portion of said metal sill, said groove means and said leg being spaced apart and extending longitudinally and parallel to each other, and outwardly extending projection means on the outer portion of said leg; a downwardly and vertically extending leg means on said plastic partial threshold, each of said leg means being spaced apart and extending longitudinally and parallel to each other, a hooked means on said downwardly and vertically extending leg means and an enlarged projection means on the end of said downwardly and outwardly leg means; and said groove means being slidably engageable with said enlarged projections means, and said outwardly extending projection means being slidably engageable with said hooked means; whereby when said integrally formed means on each of 3 ,774,343 5 v 6 said metal sill and said plastic partial threshold are slidcally extending leg forms a hooked member for slidably ably engaged, said metal sill and said plastic partial engaging Said hooked means threshold are locked together 9. The structure of claim 7, wherein said sill is an ex- 8. The structure of claim 7, wherein said downwardly d a] h d l h h and vertically extending leg means on said plastic par- 5 ed ummum S ape an Sal p asuc Pam t res tial threshold terminates at said hooked means, and Old is a Polyvinyl chloride P said projection means on the outer portion of said verti- 

1. A threshold structure for a doorway, comprising: a generally horizontal metal sill and partial threshold for extending across the bottom of the doorway; a generally horizontal plastic partial threshold for extending horizontally across the doorway and for being locked on said metal sill and partial threshold; a portion of said metal sill and partial threshold extending upwardly and inwardly to form a partial threshold; a portion of said plastic partial threshold extending outwardly and downwardly away from said metal sill and partial threshold and free of contact therewith; locking means on said metal sill and partial threshold for interlockingly receiving locking means on said plastic partial threshold; and locking means on said plastic partial threshold for interlockingly receiving said locking means on said metal sill and partial threshold; said locking means on said metal sill and partial threshold comprising an upwardly facing groove and a downwardly extending leg having a projection outwardly thereon on said partial threshold, said groove and said leg being spaced apart and extending longitudinally and parallel to each other; and, said locking means on said plastic partial threshold comprising a downwardly extending leg having a projection thereon integrally formed therewith for being interlockingly received by said groove on said partial threshold on said metal sill and partial threshold and a downwardly and vertically extending leg having a hooked member thereon and integrally formed therewith for being interlockingly received by said outwardly extending projection on said downwardly extending leg on said metal sill and partial threshold; whereby when each of said locking means are engaged, said plastic partial threshold and said metal sill and partial threshold are locked together.
 2. A threshold structure as defined in claim 1, wherein said metal sill and partial threshold extends outwardly of the doorway then downwardly to define an outwardly facing edge surface.
 3. A threshold structure as defined in clAim 2, wherein said outwardly facing edge surface has an undercut groove therein and extending longitudinally across the doorway said groove being adapted to receive a resilient strip of material for projecting from said edge surface for yieldable engagement with an auxiliary door.
 4. The threshold structure of claim 1, wherein said metal sill and partial threshold is a single piece of aluminum and said plastic partial threshold is a single piece of plastic.
 5. The threshold structure of claim 1, wherein said metal sill and partial threshold is an extruded aluminum shape and said plastic partial threshold is a PVC plastic shape.
 6. The threshold structure of claim 1, wherein said downwardly and vertically extending leg on said plastic partial threshold terminates at said hooked member.
 7. A threshold structure for a doorway consisting essentially of two one-piece components, a metal partial threshold and sill for extending horizontally across the bottom of the doorway and a plastic partial threshold for extending horizontally across the doorway on said metal sill, a portion of said metal sill extending upwardly and inwardly; leg means on said plastic partial threshold extending downwardly and outwardly away from said metal sill and free of contact therewith; and a pair of integrally formed means on each of said upwardly and inwardly extending portion of said metal sill and said plastic partial threshold which are slidably engageable with each other; said means for slidably engaging said metal sill with said plastic partial threshold comprising an upwardly facing groove means and vertically extending leg on said upwardly and inwardly extending portion of said metal sill, said groove means and said leg being spaced apart and extending longitudinally and parallel to each other, and outwardly extending projection means on the outer portion of said leg; a downwardly and vertically extending leg means on said plastic partial threshold, each of said leg means being spaced apart and extending longitudinally and parallel to each other, a hooked means on said downwardly and vertically extending leg means and an enlarged projection means on the end of said downwardly and outwardly leg means; and said groove means being slidably engageable with said enlarged projections means, and said outwardly extending projection means being slidably engageable with said hooked means; whereby when said integrally formed means on each of said metal sill and said plastic partial threshold are slidably engaged, said metal sill and said plastic partial threshold are locked together.
 8. The structure of claim 7, wherein said downwardly and vertically extending leg means on said plastic partial threshold terminates at said hooked means, and said projection means on the outer portion of said vertically extending leg forms a hooked member for slidably engaging said hooked means.
 9. The structure of claim 7, wherein said sill is an extruded aluminum shape and said plastic partial threshold is a polyvinyl chloride plastic. 